Concentrator



r-l v.29,1927. 1,650,725

A` H. STEBBINS NNNNNNNNNNN OR Filed July 19. 1926 3 Sheets-Sheet 1 j, NIMH 'if I I/ 64/ 30 ATTORNEY Nv.29,19z7. y 1,6o,725

^ A. H. STEBBINS CONCENTRATOR Filed July 19, 1926 3 sheets-sheet 2 Nov. 29, 1927. I 1,650,725

- A. H. s'rEBBlNs CONCENTRATOR Filed ul 19, 1926 3 Sheets-Sheet 3 the deck than at its inner periphery.

Patented Nov. 29, 1927.

PATET rasant ALBERT H. STEIBBIN'S, OF LOS ANGELES, CALIFORNIA.

coNcnNTaAron. y

Application sled July 1e,

rlhis invention relates to circular 4concentrators. p

Various attempts have been made heretofore to develop a satisfactory form of circular concentrator, but difficulty has been eX- perienced in developing a satisfactory construction, due to the fact that kin circular concentrator decks the progressive or oscillatory movement imparted to the deck is necessarily greater near the outer periphery (if t therefore follows that if the materials being treated are permitted to move radially of the deck while traveling over the deck surface they are subjected to a progressivemove ment that increases in intensity as the materials approach the outer periphery of the deck and which decreases in intensity as the materials approach the inner periphery, of the deck. In the circular deck constructions employed heretofore this variation in the strength of the progressive movement imparted to the materials upon different parts of the deck has made it kdiiicult to secure the desired separation of the materials.

One of the importantfeatures of the present invention therefore resides in the construction of a circular deck whereby the materials being treated arev caused to travel in channels which are arranged concentric or approximately concentric with the central axis of the deck, and as a result of this construction the materials traveling' ina particular channel remain the same distance from the axis of the deck while traveling throughout the length of the channel. It therefore follows that thematerials ina particular channel may travel entirely around the deck without being subjected to a change in the intensity of the progressive movement. l e

One of the principal advances of a circular concentrator over the usual table concentrator, resides in the fact that by causing the materials to travel in the path of a circle instead of in a straight line, a relatively long distance of travel for the materials maybe obtained on a small machine, and this is particularly desirable when fine materials which do not separate rapidly are being treated. 1

Another feature of the present invention therefore resides in the construction whereby the materials being treated may be advanced r upon the deck surface over a path that makes 1926. Serial No. 123,332.

more than one complete revolution u on the deck surface so thaty the material elivery ends of the channels extend around into overlapping relation with the material receiving ends of the channels.

Another feature of the invention resides inthe construction of the material receiving channels whereby the concentrates Vthat gradually work down in the channels under the tailings crowd the tailings out of the channels. A. further feature resides inthe construction whereby smoothk gradually widening spaces are provided between the channels. l'llhese spaces are formed by de.-

creasingthe width and depth of the channels as they approach the concentrate wall, and the spaces help to effect the separation of the materials being treated, due to thetend ency of the coarse particles crowdedout of the channels to move laterally of the spaces more rapidly than the fine particles.

Still another feature of the invention resides in the construction of the operating means provided tol impart a.V progressive y'oscillatory movement to the deck to advance vention, the supporting frame being shown f in end view and the deck in vertical section;

Fig. 2 on an enlarged scale is a perspective view of the deck of Fig. l;

Fig. 3 is a top planview showing a modi- Y tied type of deck' mounted upon the supporting frame of Fig. l;

Fig. 4.- is a side elevation of the concentrator of Fig. 1; f

Fig. 5 on an enlarged scale is a perspective sectionalpview ofa modied deckconstru tion;

Fig. 6 is a view similar to Fig. 5 but shows still a different form of deck construction, and

Fig.` 7 is afragmentary, transverse, sectional-view of 'a portion of the deck, the view being taken near the discharge end of several of .the channels.

The frame of the circular deck or table may be constructed of an annular casting having the central hub 11 ywhich is connected to the ouberportion of the casting by the yspokes 12. Upon the annular casting 10 are the inner annular wall 14. These features, however, may be varied as desired.

v The frame for supporting the deck or table for rotative movement may be varigously constructed and as shownis formed of the sijderails 15 that are secured to the `uprights 16 and the. sides of the frame are connected by the transversely extending braces 17. n

A `The concentrator deck or table is supported by its frame for rotative movement vin'ya horizontal plane, and this is accomplished-in the construction shown by rigidly vsecuringthe hub 11 of the deck casting, to .the4 upper end of a vertical shaft 18V, and -thisshaft is journaled in the spaced bearing `brackets 19 and 20, these brackets bef. ing mounted upon the centrally disposed `V-rails/21 of they supporting frame. The weight of the deck is preferably supported 'by the antifriction bearings 22 positioned between the upper end of the bearing bracket and the under face of the hub 11. As above stated an important feature of the present invention resides in the construcw tion of the Adeck surface and of the channels i "i111 which the materials travel while they are being separated, and the deck construction 55, shown in Figs. 1 and 2 of the drawings will now be described. Thevdeek surface-,23 maybe formed of lsheet metal, wood or any other suitable mate- ,rial and is arranged to form a. receptacle or bowl having the shape of a frustrum of a cone' the inclined walls of which slope downwardly toward the central axis of the deck, the arrangement being such that the materials that escape from the material receiving channels lwill flow down the inc-lined deck Asurface toward the inner annular wall 14 of the deck. The deck surface 23 may besupported in spaced relation to the annularcasting 10, and at the desired inclination to said casting by the inclined bars 24 the outer ends of which ,may bey secured to the outer wall 13 of the deck and the inner ends of whichfymay be secured to the -inner wall 14.

The materials to be treated may be delivered to the decksurface by a hopper 25 preferably disposed near the outer periphery of the circular deck, and the rate at ,which the materials are delivered to the deck surface. by the hopper will vbe controlled by a sliding gate 26. The deck surface 23 is preferably constructed to form the material receiving channels 27 which yare arranged .concentric or substantially concentric with the central axis of the circular deck, as will i be apparent from the drawings. If the ma- 25 terial receiving channels 27 are made relamounted the upstanding outer wall 13 and complished inl accordance with the present invention by providing each channel 27 near the feed hopper with an upstanding wall or riiile 28 which is disposed at the inner curved edge of the channel, as best shown in Fig. 5. These riiiles 28 may be formed of a narrow strip of sheetr metal that may be tacked, soldered, or otherwise secured to the upstanding wall 29 of a channel, and the riiiles preferablygdecrease in height in the direction in which they extend away from the hopper 25,`

so that they gradually disappear at points some distance from the feed hopper 25, as will be apparent from Figs. y2 and 3.

The material receiving channels 27 are preferably formed upon the deck surface 23 by giving the same the stepped construction best shown in Figs. 5 and 6, wherein it should -be noted thateach channel consists of an upstanding wall 29 and an inclined iioori portion 30, and it will be seen that the floor portion slopes downwardly as it extends outwardly away-from the central axis of the circular deck. As a result of this constructioneach channel lhas t-he form of a trough adapted to receivevthe concentrates C, asindicated in Fig. 5. The construction is such that as the materials travel along the channels 27 under theinfiuence of the deck movement, the concentrates will gradually work down under the lighter materials or tailings, and these tailings will escape inwardly over the riiiies 28 yas these riiiles gradually decrease in height, and will also flow inwardly at various points along the channels -as they are crowded out of the channels by the concentrates. This tendency of the concentrates to crowd the tailings out of the channels may be increased by gradually decreasing the depth of the channels in the direction in which they extend, so that' these channels become more and more shallow as they approach the concentrate wall, to be described.

The hopper 25 preferably does not extend entirely across the deck surface, but serves to deliverniaterials to be treated only to the channels 27 that are located near the outer wall 13 of the deck surface. As a result of this construction the tailings and any of the concentrates that are crowded out of the outer channels 27 will enter other channels disposed near the inner wall 14 of the deck, for further treatment.

As the materials within a channel 27 reach the end of suchchannel they are directed CTL against a concentrate wall 31 having the buffer blocks 32 which give the wall the stepped construction shown, and the arrangement of this wall is'such thatit serves to gradually direct the concentrates inwardly from the outer portion of the deck towards the inner wall 14. The concentrate wall 3l, however, `need not direct the concentrates entirely across the deck surface, but may direct them into the channels 33 (see Fig. 2) along which the concentrates may travel until they reach one or more receptacles 34 adapted to receive the concentrates. The tailings that gradually work downwardly towards the inner wall 14 of the circular deck as they vare crowded out of the channels will pile up against the inner wall 14, along which they may travel under the progressive movement imparted to the deck until they reach the discharge opening 35 through which they may pass into a tailing discharge hopper 36 that may be supported in the position indicated in dotted lines in Fig. 4.

The movement imparted to the circular deck to advance the materials along the ychannels 27 serves to throw the materials ln some cases it may be desirable to make `the channels 27 longer than those shown Fig. 2 without at the saine time increasing the diameter of the circular deck. kThis may be done in accordance with the present invention by constructing the channels 27 as shown in themodified construction of 'Fig'. 3 wherein it will be seen that the materials being treated are directed around the concentrator deck through more than one complete revolution. This is accomplished by arranging the channels 27 so that the deliv-V ery end of some of the channels overlap the material receiving ends of other channels, as will be apparent from Fig. 3.` The con centrate wall 31 shown in the modified construction of Fig. 3, it should be noted, eX- tends spirally over the deck surface through nearly a complete revolution and serves to 'direct the concentrates gradually inwardly from the outer portion of the deck surface to points near the inner wall 14 of the deck where the concentrates escape through the discharge pipes 37. The tailings in the construction shown in Fig. 3 may escape through an opening in the inner wall 14 of the deck and fall into the hopper 36, as in the construction of Fig. l. The advantages secured through the use of a long deck reside not only in the fact that a better separation of the materials may be effected than can be secured when a short deck is used, but reside also in the fact that when a long deck is employed the materials may be fed l tothe deck from the feed hopper in a much thicker layer than is practical when a short deck isemployed. This is due to the fact that when a long deck is employed the thick layer of materials has ample time to spread out and stratify before reaching the .concentrate wall, while when a short deck is employed it is necessary to feed the materials to the deck `in a relatively thin layer in order to insure the desired separation of 'the materials before they complete their be energetic enough to disturb the stratification of the materials which gradually takes pla-ce over the deck surface. A good practical construction for imparting the desired oscillatory movement to thecircular deck is shown in the drawings and will now bedescribedr` The concentrator deck is provided with a cable `receiving drum 38which may be formed integral with the supporting casinglOof the deck, and the drum 38 is adapted to receive the operating cable 39 which may be wrapped one or more times around the drum and isl preferably secured thereto bya clamp 33l constructed to prevent `the cable from slipping about the drum. The deckr is rocked about its supporting shaft `by pulling first one end of the cable 39 and then the other, and this is accomplished in accordance with the present invention by connectingthe ends of the cable 39 to the oppositely extending arms of a crankshaft 40, the ends of which shaft are rotatably mounted in bearing brackets 4l that are secured to the main frame. The crank shaft 40 is provided near oneside of the supporting frame with the laterally extending arms 42 that are connected by the wrist pin 43 and this crank shaft is provided near t-he opposite side of its supporting frame with the laterally extending arms 44 which are connected by the wrist pin 45. One end portion 46 ofthe operating cable 39 is led over a grooved sheave 47 and then extends down- Ywardly to the wrist pin 45 to whichit is secured, and the opposite end portion 48 of the cable 39 is led over a grooved sheave 49 and extends downwardly from this'sheave to the wrist pin 43 to which the end of the cable is secured. The sheaves 47 and 49 are tilll rotatably supported by a transversely'extendingshaft the ends of which are journaled in: bearing brackets 51 secured to the supporting frame.

Y The crank arms just described extend in opposite directions, as clearly shown in Fig. 1, and it will therefore be seen that as the crank shaft 40 is rocked in one direction it will tension one operating cable and slack off/the other to rotate the circular deck in one direction, and as the crank shaft 40 is rocked in the opposite direction it will actuate' the cable 39 to pulll the circular deckin the opposite direction. In order to impart a progressive movement to the materials upon the deck surface yit is necessary to move the deck more energetically in one direction than in the other. This is accomplished in an extremely satisfactory manner by the .operating mechanism just described since as the crank shaft 40 is moved to the position in which the crank arms lie in a vertical plane as shown in Fig. 4, the speed at which one cable is let off and the other is taken up decreases as the crank arms approach this position, and as the. crank arms are moved to an angle tothe position in which they are shown in Fig. 4, the speed at which one cable is taken up and the other is let 0H will increase as the crank arms approach a horizontal position. In other words, the angular movement of the crank arms is utilized to impart a variable speed movement to the opposite ends of thev deck operating cable. It will benoted that the idle sheave 49 upon the shaft 50 is larger in diameter than the idle sheave 47. This is desirable because it lifts one coil of the cable about the drum 38 above the other, so that they will not interfere with each ot-her and also because this construction helps to maintain a uniform tension on the opposite ends of the cable 39 as the crank shaft is rocked back and forth'.

The desired progressive movement may be imparted to the materials upon the deck surface by rocking the deck through a` small angle`r and it is therefore necessary to rotate the crank shaft 40 through only a small part of ya complete revolution, say through an angle of not more than o or 25. Various means might be provided for imparting this rocking movement to the crank shaft r'and in accordance with the present invention this is accomplished by providing an operating cable 52 one end of which is sccured to the upper wrist pin of the crank f (se shaft 40 and the other end of this cable is anchored to the supporting frame by an adjustable bolt 53. An intermediate portion of the cable 52 is looped about a grooved sheave 54 that is mounted upon an eccentric 55. A second operating cable 56 has one end secured to thelower wrist pin 43 of the crankshaft and the other end of this cable is anchored to the supporting frame by an adjustable bolt 57, While an intermediate portion of the cable 56 is looped about a grooved sheave 58 which is mounted upon the operating eccentric 59. The operatingr eccentrics and 59 are mounted upon and are rigidly secured to the power operated shaft 60 the ends of which shaft are journaled in the bearing blocks 61 mounted upon the supporting frame. The ecccntricsfi and 59 are preferably' spaced at an angle of 180 to each other and as the power shaft G0 is rotated these eccentrics rotate within their respective sheaves 'and move Y, the sheaves through orbital paths to thereby alternatively tension and slack off the cables 52 and 5G. This will serve to rock the crank shaft 40 back and forth between the positions in which it is shown in full linesand in dotted lines in Fig. 4. The speed at which the circular deck is rotated will gradually decrease as the crank arms approach the full line position of Fig. 4 and the speed will gradually increase as the arms are movedrto the inclined position indicated in dotted lines in Fig. 4. This variable speed movement imparted to the deck will serve to advance the materials in the channels 27 from the feed hopper 25 towards the concentrate wall 31 in a very satisfactory manner. The power operated shaft 6()4 is preferably provided with a fly wheel (not shown) to steady its rotative movement.

The separation of the materials upon the deck surface may be assisted by the use of surface and to this end air apertures may be `formed within the deck surface throughout the length of each channel 27. or if desired the apertures may be formed in only that portion of the channels which lie near the feed hopper; in any event. when air is cmployed to promote the separation of the materials the strength of the air should be strongest near the feed hopper and should gradually decrease as the channels approach the concentrate wall. This may be accomplished by reducing the number and size of the apertures formed along the channels 27. In the modified construction shown in Fig. 5 the concentrator deck is formed of wood and the channels 27 are produced bv cutting such channels in the upper face of the wooden deck 62. In the modified construction shown in Fig. 6 the deck construction differs from that shown in Figs. 1 and 2 in that a separate air chamber is formed below each channel 27, these air chambers being produced by providing the vertical walls or partitions 63 below the deck surface and which extend upwardly from the floor plate G4. This modified construction of Fig. 6 permits complete control of air passing up- Wardly through .the apertures G5 in any channel and constitutes a stiff and durable inclusive.

As above stated f theniater'ial receiving channels 27 preferably grow more shallow as they approach,therconcentrate wall,` as

will he apparent from Fig. 7 where some of the channels 27.1 areshown' as quite shallow'and as having tliesmootlrspaces 66 bctweenv them. Thea-spaces 66 which gradually increase in width near the'concentrate wall are not waste portions of the deck sure face, hut are `useful because by the time the materials heilig treated approach the `concentrate. wall the line tailings will have been crowded or forced rout'fof the channels `so that there will remain vthe fine and coarse values and the coarse'tailings. A As the coarse tailings and tine values are crowded out of the channels 27k onto the surfaces 66 the tail-l ings will slide or roll quicklyoverthese surfaces in the direction in which they slope,

while the fin-e values will travel across these surfaces more slowly.. In this manner the smooth surfaces 66 help to separate the fine values from the tailings and this particular separat-ion is assisted by the direction of deck. y

lWhat is claimed is y l. A circular concentrator deck, comprising in combination, a deck frame having a frusto-conical shaped deck surface the ccnter of which is open and which surface slopes downwardly towards its central axis to direct the tailings down the inclination of the deck toward said central opening, material receiving channels formed upon the deck surface and constructed so that they extend around the deckthrough more than one complete revolution upon a single deck surface and having their forward 'and rear ends disposed in overlapping` relation upon a non-overlapping deck surface.

2. A circular concentrator deck, comprising in combination, a deck frame having an annular deck surface and provided with material receiving channels formed upon the deck surface and disposed so that they` d1- rect the concentrates entirely around the deck through one complete revolution and partly around the deck a second time while they remain in the same plane upon the deck surface, and means for oscillating the dec-k to advance the materials along the channels.

3. A circular concentrator deck, comprising in combination, a deck frame having an annular deck surface and provided with a tailing discharge opening and with curved riiies, a concentratecwall provided upon the deck surface to extend in aspiral manner over the deck surface and constructed to direct the concentrates progressively inwardly from the outer wall of the deck to positions near 'the inner periphery of the annular deck Surface and means for oscil-f lating the deck to advance the materials around the deckj,`

y 4. Acircularconcentrator deck, compris# ing in combination, a deck frame having a, frusto-conical` shaped deck surface that slopes downwardly towardits centralaxes, ritl'les for directing the materials around fthe deck surface and arranged to arrest the iowl ofthe materials toward thecenter of they ing in combination, a deck frame havingan` annular deck surface, material receiving channels formed upon the deck surface Aand constructed so that they extend around the deck through more than one complete revolution and are arranged with their material receiving ends disposed near the outer periphery of the deck while their delivery ends lie near the inner periphery of the deck and n in overlapping relation to the material removeineiit imparted to the materials bythe ceiving ends.

frustofconical shaped deck surface that` slopes "downwardly toward its central axis and which is provided with a stepped con` struction in cross section to forin material receivingchannels, and each channel having an inclined floor that slopes downwardly in a direction to direct the materials outwardly away lfrom the center of the deck, and Y means for oscillating` the deck to advance the materials along the channels.

7. A circular concentrator decln'comprising in combination, a deck frame having an annular deck surface, material receiving channels formed upon the deck surface and constructedso that they extend around the l deck through more than one complete revoupstanding wall portion and a floor portion that slopes downwardly aWav from the central axis of the deck to the wall portion and adapted to direct the-heavier materials outwardly into the deepest portion of the chaninJ nel where they workdownwardly under the lighter particles, and ,meansgfor oscillating 'the deck to advance the materials along` the channels. ,g y i q V 9. A circulareoncentrator deck, compris,- ng in combination,A a rusto-conical shaped decksurface that is provided ywith material receiving channels extending in a curved path about the deck surface, said channels being formed with inclined doors thatslope from the inner side of a channel ina downward direction awav from the central axis of the deck toward the outer sideof the chan- Y nel to produce channels that gradually increase `in depth -froin their inner to their outer sides. e l i t s 10.y A circular concentratorV deck, comprising in combination, a deckframe havment to the deck frame, and a retaining wall provided at the inner periphery of the deck surface and adapted to confine the tailings for further treatment as they travel around the deck surface against said'wall.

In testimony whereof, I have signed my .c naine to this specification.

ALBERT H. STEBBINS;fL 

